Submersible pump device for net brailing



Aug. 27, 1968 D. w. LERCH 3,398,694

SUBMERSIBLE PUMP DEVICE FOR NET BRAILING Filed Aug. 11, 196e 2 Sheets-Sheet l INVENTOR. A Av/D w. 452cv/ Aug- 27, 196s D. w. LERCH 3,398,694

SUBMERSIBLE PUMP DEVICE FOR NET BRAILING Filed Aug. ll, 1966 2 Sheets-Sheet 2 A from/5K6' United States Patent O 3,398,694 SUBMERSIBLE PUMP DEVICE FOR NET BRAILING David W. Lerch, Iquique, Chile, assignor to Marine Construction & Design Co., Seattle, Wash., a corporation of Washington Filed Aug. 11, 1966, Ser. No. 571,777 15 Claims. (Cl. 103-87) ABSTRACT OF THE DISCLOSURE AHigh-capacity heat exchange means for the encapsulated hydraulic drive motor of a submersible liquid or liquidsolids pump are provided by encasing the motor unit in a heat exchange pod situated in the pump passage and delining a hydraulic fluid space surrounding the motor. Pressurized hydraulic liquid from the motor discharges into this space for cooling through the pod wall before iiowing in the return conduit to the hydraulic pressure source. In the illustrative embodiment, dow-directing vanes mounted on the pods exterior downstream from the pump serve in a multiple capacity, providing added heat-exchange surface area, serving to convert kinetic energy of the pumped liquid into axially directed pressure and ow, and as shield or housing for the reach of coaxial hydraulic supply and return lines extending across the pumped liquid passage. Other configurational features also appear in the illustrative embodiment.

This invention relates to improvements in pump devices of a type which may be used in accordance with the method and apparatus concepts disclosed in my copending application Ser. No. 580,055, filed Sept. '16, 1966, now Patent No. 3,314,184, a continuation of `Ser. No. 394,681, filed Sept. 8, 1964, entitled, Apparatus for Pumping of Fish, now abandoned. While the present invention was devised primarily for such applications, it will be observed that the novel features may be incorporated in other applications for pumping of liquids, and particularly for pumping of liquids with solid objects from a submerged location. The invention is herein illustratively described by reference to the presently preferred embodiment thereof; however, it will be recognized that certain modifications and changes therein with respect to details may be made without departing from the essential features involved.

An object hereof is to provide a device of the described type which will pump at high rates efficiently without damaging the fish. A related object is to provide a pump device of a general configuration, weight distribution and relative positioning of inlet and outlet openings such that the device may be suspended by cable on a flexible pressure hose in a net without interference with or from the net and with the inlet at all times efiiciently directed to receive lfish. Likewise because of the described relationships the location and orientation of the pump device will be determinable by inspection of the hose or suspension line even though the device itself may be practically invisible inthe depths of the net while pumping during the early stages of drying up the net. Compactness, lightness of weight, convenience of assembly and disassembly, ruggedness, durability, simplicity of construction, and suitability for operating in a marine environment and submerged over prolonged periods represent still other objectives of the invention.

A further and important object is to devise a submersible hydraulically driven pump wherein problems of brine leaking into the pump bearings and other parts are minimized, where pump lubrication problems are eliminated and wherein efficient cooling of the hydraulic fiuid 3,398,694 Patented Aug. 27, 1968 ICC in the operating circuit of the pump motor is achieved conveniently using the pumped liquid itself as the cooling medium.

A specific object hereof is to provide a fish pump and the like wherein transitions of pressure to which the lfish are subjected in passing through the pump device are made gradually and along 'flow paths involving no abrupt changes in direction of movement.

As herein disclosed the improved pump comprises a generally tubular housing preferably of elongated round cross section having a central axis and being open along the axis to form respectively a pump inlet and outlet. The housing is bulged intermediate its ends and an inner pod preferably of streamlined configuration is mounted coaxially within the bulge cavity to form therewith an axially symmetrical flow passage which Varies in cross section and merges with the pump inlet and outlet at the ends of the pod. The pump impeller is mounted in this passage at a location adjacent the inlet where the passage is divergent inwardly from the inlet, and the generally radial and curved impeller vanes are therefore angled to the housing axis such that 'fish drawn through the inlet follow a general flow direction with no abrupt changes in traversing the impeller and continuing beyond it to the outlet. The pump motor, mounted in the pod casing, dischatges directly into the casing interior. The pod thereby also serves as a heat exchanger for the hydraulic liquid. Fins on the pod effectively increase the pods external cooling surface for heat exchange with water being pumped through the device. These same fins serve as flow columnating vanes converting the swirling flow of liquid leaving the impeller into generally axial ilow in the passage approaching the outlet. Preferably, hydraulic pressure and return conduit means for the motor extend through one of these vanes.

For fish pumping applications wherein the pump device is hung over the side of a 'fishing vessel, the unit is preferably suspended by a bridle with its axis vertical as an effective downward continuation of the pressure hose to which the device is connected. A projecting elastic bumper on the housing protects the parts against damage by impact with the vessel. A screen mounted over the inlet orifice limits the size of fish that may enter and is supported in this position by outer bars formed in a domed configuration which fend the net mesh, massed fish and large objects away from the screen.

The housing of the unit is preferably formed in three sections for ease of manufacture and of assembly, the upper or outlet section being joined to a midsection adjacent the transverse plane of maximum cross section of the housing, and the lower or inlet section being joined to the midsection along the upwardly diverging portion of the housing at a transverse plane where the crosssectional diameter is sufficient to permit insertion and removal of the pump impeller with the inlet section removed.

These and other features, objects and advantages of the invention will become more fully evident from the following description thereof by reference to the accompanying drawings.

FIGURE 1 is a perspective view of a portion of a purse seine net as it is being dried up so as to concentrate its catch of fish into a small space, the view showing the pump device suspended in the net in order to transfer fish to the adjacent vessel (not shown).

FIGURE 2 is an axial sectional view of the assembled pump device.

lFIGURE. 3 is an exploded isometric view of the pump device, with some parts broken away in section so as to reveal details.

In FIGURE l the submersible pump device P is shown c Y 3 suspended by bridle B on a fish within the closed pouch of a partially dried-up purse seine net N. The net would be manipulated andheld in the usual manner from the side of the fishing vessel (not shown). A flexible pressure hose D, preferably of lightweight rubberized fabric, leads upwardly from the upper or delivery end of the pump device to the deck of the vessel where the water-home fish may be discharged from the hose into and through a suitable dewatering device (not shown). Bridle B is connected to diametrically opposite lugs 19 located on the upper portion of the pump housing 1 such that the unit hangs pendulously from the bridle with its central axis A-A disposed vertically and asy an effective downward continuation of hose P. 4The pump device comprises an outer housing 1 formed in three main sections 1f), 11 and 12 joined on transverse planes. The 'bottom section 11 forms a downwardly flared inletoritice 14 -opening directly downward along axis A-A. The top or outlet section forms a converging outlet orifice adapted for connection to the pressure hose D by band clamps D1 as depicted. The outlet orifice opens directly upward along axis A-A. The intermediate section 12, interconnects the top and bottom sections.l

Bolts 13a, with head recessed, join together the top and intermediate sections, whereas bolts 13 join together the bottom and intermediate sections. Between its ends the generally tubular housing swells to a maximum cross section substantially at a transverse plane coinciding with the joint between sections 10 and 12, so as to form a bulbous pump cavity therein.

Mounted coaxially within the bulbous portion of the generally tubular outer housing 1 is a pod unit 2 of generally tear drop or streamlined configuration conformed approximately to the housing interior on all sides and spaced inwardly therefrom so as to form a ow passage 21 of annular cross section and changing diameter surrounding the pod. This passage 21 merges smoothly with the inlet and outlet orifices 14 and 15 at the ends of the casing 1. Near its lower end the passage 21 diverges upwardly from the inlet orifice 14 at an acute angle to axis A.A. The pump impeller 41 is mounted in this divergent portion of the passage just above the inlet orifice 14. At the top, the passage 21 converges to the outlet orifice 15 at an acute angle to axis A-A. The impeller hub 4, of generally conical form having its apex directed downwardly along the axis A-A, provides a streamline nosing yfor the bottom of the pod 2. The impeller also has an annular outer rim 4a of generally truste-conical shape lying closely along the interior wall of the housing 1 adjacent the inlet orifice 14, such rim being joined to the hub 4 by the generally radial impeller vanes 41a which are angled to axis A-A in a longitudinal sense and curved ci-rcumferentially along the flow path in order to effect pumping. inasmuch as the diverging and converging portions of the housing adjacent the pump inlet and outlet have an acute angle relationship with the axis A-A, and the impeller is mounted in such passage adjacent the inlet, the water and fish move very etiiciently through the device and encounter no abrupt changes of direction in traversing the pump. Moreover, the flow passage 21 is unobstructed Ifor a short portion of its length above the impeller 41 so that fish will be more or less fully clear of the after-tips of the impeller vanes 41a before they reach the transverse plane defined by the leading edges of the columnating varies a (FIGURE 2).

Pour dow-directing -or columnating vanes, 'arranged in quadrature, having lower sections 20a and upper sections 20, extend radially between the pod 2 and the housing 1 in generally axial planes. Their lower leading edge portions curve circum-ferentially against the direction of swirl of water leaving the impeller so as to efiiciently intercept and redirect the swirling water and fish into longitudinal flow. Lower vane sections 20a rigidly interconnect housing section 12 with the lower section 2b of the pod casing. The upper pod section 2a is detachably joined by bolts cable C in a concentration of n'at Zdtto the lower pod section2b along a transverse plane substantially coincident withthe joint plane of outer housing sections 10 and 12. Upper vane sections 20 extend upwardly substantially to the outlet orifice 15.

A hydraulic motor 3 'for driving the impeller 41 is mounted in the hollow interior space 2c formed by the casing of pod 2. The motor shaft 3a projects axially through the bottom of the pod casing, antifrictionally supported therein by bearings 40 vwhich are sealed by bearing seals 4021.7The motors discharge portf3a opens directly into the interior space 2c'of the casing. The hot liquid discharged by the motor is thus free to circulate around the pump housing and,Y fo'r'icooling purposes, in direct contact with the surrounding pod4 walls. The effective heat exchange surfacearea of the pod is increased greatly by the vanes 2li-20a. Such hydraulic uid vdischarged from thev pump and collected` in Vthe space A2c Aflows outwardly through a passage 21cz in one (20') of the vanes 20 which is thickened for vthis purpose intermediate'its upper and lower edges. A chamber Ztl'b is formed on the outer edge of the vane 20', which chamberprojects through a conf forming aperture 10a inthe outer housing section 10. AA

, pressure supply conduit 31 or a fitting (not shown) ythereon projects Vfrom the inlet 33 0f motor 3 through vane 20 and out one opening in chamber 20b for carrying hydraulic pressure fluid to the motor 3. The chamber has a second opening and hose fitting 32 offset from the conduit 31 for returninghydraulic pressure fluid to the rcmote hydraulic pressure source (not shown). The respective hydraulic hoses are designated 31a and 32a in FIG. URES l and 2. The hose fittings mounted on the charnber Ztlb are located adjacent the housing outlet at 15 and are directed approximately parallel to the axis, so that the hoses 31, 32 may lie close alongside the pressure hose B in the suspended operating position of the pump and so that the fittings will be protected against dam-age should the pump -device bang against the side ofthe fishing vessel in heavy seas.

In order to protect the unit against damage by slammingA against rigid surfaces, an annular rubber -bumper 12a is mounted on the intermediate housing section 12 and projects radially outward lbeyond any other parts of the pump device. Below this bumper the pump device has an inverted dome-shaped net vfender in the form of rigid bars, 5, the upper ends of which are detachably mounted at langularly spaced locations on the bottom of housing secl tion 12 4by way of a carrier ring 5a clamped to the housing by bolts 13 and lugs 13b, These bars turn inwardly to a second, lower carrier ring 5b mounted below and in coaxial alignment with the orifice 14, where they support an inverted dome-like screen 50 overlying the orifice 14 so as to exclude tish over a certain size. i

In addition to serving as a heat exchanger for hydraulic tiuid discharged from motor 3, lthe pod casing protects themotor against infiltration of brine should a leak develop at any of the seals, since any tendency for leakage will be from the inside out due to the greater pressure of the' hydraullc fluid 1n the space 2c than the pressure of water,

in the space 21. This arrangement thereby also assures lubrication of bearing surfaces in the motor. It will be appreciated by those skilled in the art that an improved fishl pump device achieving the above-memtioned and related objectives may be embodied in variant forms within the framework of the inventive concepts.

However, the illustrated embodiment is consideredto be of optimum form and design so as to achieve these'various objectives in a. degree which isunique. Thus while the invention broadly embraces the concept of mounting a hydraulic drive motor for the pump impeller inside apod and passing the heated hydraulicfluid into the pod interior space surrounding the motor for cooling, with the pod casing itself serving as a heat exchanger surrounded" by the pumped liquid traversing the housing interior, it will ,be recognized that the particular housing and pod form and arrangement of parts yield a combination of related advantages, especially for fish pumping applications, unique to this art. It will also be noted that the vertically aligned inlet and outlet openings interconnected bythe convergent-divergent bulbous pump cavity enclosingthe pod unit, providing combined axial and angled ow in an annular passage merging with the inlet and outlet, make for efficient pumping at high rates with minimal damage to the fish, and convenient reliability in the positioning of the unit on a pressure hose, whether in a net or in the hold of a vessel which is to be unloaded. These and other aspects of the invention including equivalents thereof will be apparent from an understanding of the subject matter as disclosed and as set forth in the claims which follow.

I claim:

1. A submersible pump for pumping liquids and liquids with solid objects suspended therein, comprising a generally tubular housing of substantially round internal cross section having a central axis and being open along said axis to form respectively a pump inlet and outlet, said housing having an internal cross section which is maximum in a transverse plane intermediate said inlet and outlet and which progressively decreases toward said inlet and outlet, thereby to provide a bulbous doubly-tapered housing cavity, a pod unit exteriorly of doubly-tapered form supported coaxially within said cavity spaced inwardly on all sides from the cavity wall to dene therewith an annular liquid passage which is substantially symmetrical about said axis and merges with said inlet and outlet in acute angular relationship with said axis, rotary pump means including a motor carried by said pod unit, and an impeller having vane elements located within said passage to rotate about said axis, and generally radially disposed now-directing vanes fixedly located in said passage intermediate the impeller and pump outlet to convert the swirling flow of liquid from the impeller into generally axial ow at the outlet, said pod unit having a hollow interior accommodating the motor therein, said outer surface of said pod unit being surrounded at least in part by liquid ow space adjacent the wall of the pod unit, said motor comprising a hydraulic motor, and hydraulic motor pressure fluid connecting means, including a ow space in said pod unit about said motor, forming a hydraulic pressure fiuid path extending from the motor for connection tothe exterior of said housing, whereby the pod unit wall functions as a heat exchanger between such fluid and liquid in said passage.

2. The pump dened n claim 1, wherein the flowdirecting vanes comprise heat conductive material joined directly to the pod unit to increase the effective heat exchange surface area of the latter in contact with the liquid in said passage.

3. The pump defined in claim 1, wherein one of the dow-directing vanes incorporates a radially extending hydraulie pressure fluid passage communicating at its inner end wi-th the pod unit interior flow space.

4. The pump defined in claim 3, wherein the pressure uid connecting means includes separate conduit means extending through said hydraulic pressure fluid passage from the housing exterior to the inlet side of the hydraulic motor.

5. The pump defined in claim 1, wherein the pump im peller comprises a generally conical hub mounted on the end of the pod unit with i-ts lapex directed along the axis toward the inlet and having vanes extending outwardly from said hub at an acute angle to the axis for rotation at a location in that part of the annular ow passage which diverges from the inlet.

`6. The pump defined in claim 5, wherein the housing comprises an outlet section including said outlet, an inlet section including said inlet and an intermediate section detachably joined to the outlet section substantially in a transverse plane of the housing where its cross section is maximum, and detachably joined to the inlet section substantially in a transverse plane of the housing where its cross section is diverging from the inlet and exceeds the pump impeller diameter so as to permit insertion Yand removal of the impeller by detachment of the inlet section of housing.

7. The pump defined in claim 5, wherein the housing comprises sections which are detachably joined together substantially in a transverse plane of the housing where its cross section is maximum, said fixed vanes including portions rigidly mounted on the pod unit where it converges toward the outlet, whi-ch portions are separate from the housing, and portions which rigidly interconnect the pod unit with the housing where the latter converges from said transverse plane to the pump impeller.

8. The pump defined in claim 7, wherein the pod unit comprises sections which are detachably joined together substantially in said transverse plane of the housing.

9. A hydraulically driven liquid pump comprising a hollow outer shell formed symmetrically about an axis, and having an inlet at one end and an outlet lat its other end, the shell being bulged intermediate the inlet and outlet, a hollow casing within said shell formed and positioned symmetrically about said axis, and bulged intermediate its ends to define with the shell a passage of generally annular cross section extending between and merging with the inlet and the outlet, a hydraulic motor mounted within said casing and spaced from the inner surface of the casing to define a chamber about the motor, said hydraulic motor discharging its hydraulic fluid into the chamber, a pump impeller mounted upon said motor coaxially with relation to the shell and having vanes rotative within the passage, a hydraulic fluid supply line leading to the motor, and a hydraulic fluid return line leading from the chamber in -said casing, whereby heat energy of hydraulic fluid discharged into said chamber about the motor is absorbed through the casing wall by liquid being pumped through the passage between the casing and outer shell.

10. A submersible sh pump for net brailing and the like comprising a generally tubular housing of round cross section adapted to be suspended in the water from la lishing vessel with its axis vertical and with its upper end forming a pump outlet adapted for connection to a vertically hung pressure conduit to carry the pumps discharge upwardly therein, said housing downwardly from said outlet diverging in cross section to a maximum then converging in cross section to a pump inlet so as to form a bulbous cavity between inlet and outlet, a flow-divider pod unit of generally streamline cross section mounted coaxially within said -cavity and including in said pod unit a hydraulic motor, a pump impeller connected to be driven by said motor and mounted for rotation on the lower end of said pod unit adjacent the inlet, said pod unit defining with said cavity an annular passage merging with said inlet and outlet, said pod unit comprising a hollow streamlined casing in which -the motor is mounted spaced from the interior wall thereof, said hydraulic motor discharging its fluid into the interior casing space surrounding the motor for purposes of cooling through said casing wall, and flow columnating vanes projecting from the casing into said passage and thereby functioning also as heat ex- -changer fins increasing the cooling surface area of the casing.

11. The pump defined in claim 10, including a domeshaped screen overlying the inlet to limit the size of fish permitted to pass into said inlet, and means supporting said screen detachably on the housing including a plurality of bar members having upper ends fastened to the housing at angularly spaced locations distributed about said axis and offset radially outward from said screen, and extending downwardly thence inwardly to connect supportively with the screen.

12. The pump defined in claim 11, and elastic bumper means mounted on the housing exterior intermediate the inlet and outle-t and projecting radially therefrom beyond the screen-supporting bar members.

13. The pump defined in claim 11, wherein the pump motor comprises a hydraulic motor, with hydraulic pressure supply and return conduit means extending upwardly and outwardly from the pod unit through the housing at a location ladjacent the inlet, said pod unit comprising a hollow casing in which the motor is mounted and into which it discharges for cooling of the hydraulic fluid in passing to the return conduit, and a plurality of vanes projecting generally radially from said pod unit above the impeller to columnate the ow of liquid in the passage and increase the pods heat exchange surface area therein.

14. A hydraulically driven submersible pump comprising a hollow outer shell having an inlet and an outlet, the shell being bulged intermediate the inlet and outlet, a hollow casing mounted within said shell and configured to define therewith, a liquid dow passage generally sur-` rounding said casing, which passage extends between and merges with the inlet and the outlet, a hydraulic motor mounted within said casing and spaced from the inner surface of the casing, said motor discharging its hydraulic fluid into the space between said casing and the motor, an impeller mounted upon said motor within the casing and having vanes rotative within the passa-ge, a hydraulic fluid supply line connection for conducting hydraulic iluid to the motor, and a hydraulic return line connection for conducting hydraulic fluid from said interior space of the casing, whereby heat energy of the hydraulic fluid is absorbed through the casing wall by liquid pumped through the space between the casing and outer shell.

15. A hydraulically driven submersible pump comprising a hollow outer shell having an inlet and an outlet, a

vhollow casing mounted within said shell and configured to define therewith, a liquid flow passage generally sur# rounding said casing, which passage extends between and merges with the inlet and the outlet, a hydraulic motor mounted within said casing to define a space about the motor within said casing, said motor being connected to discharge its hydraulic iluid into said space, an impeller mounted upon said motor Within the casing and having vanes rotative within the passage, a hydraulic fluid supply line connection for conducting hydraulic duid to the motor, anda hydraulic return line connection for conducting khydraulic fluidy from said interior space of the casing, whereby heat energy of the hydraulic uid discharged into said space is absorbed through the casing wall by liquid pumped through the space between the casing and outer shell.

References Cited UNITED STATES PATENTS Y 1,140,828 5/1915 Jackson et a1 103-102 1,981,991 11/1934 Cline et a1. 103-88 1,982,841 1'2/1934 Tamini 10s- 87 2,210,401 8/1940 Fulton 10s- 102 7 FOREIGN PATENTS 448,066 4/1948 canada.

653,631 11/1937 Germany.

257,111 8/1926 Great Britain.

HENRY F. RADUAZO, Primary Examiner. 

